Control apparatus



Dec. 31, R. L 2,227,309

CONTROL APPARATUS Filed Dec. 23, 1957 INVENTOR fiuberZ/Zf/i/f.

BY 3 ATT iQNEYS Patented Dec. 31, 1940 PATENT OFFICE CGNTROL APPARATUS Robert H. Hill, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware 7 Application December 23, 1937, Serial No. 181,263

Claims.

This invention relates to control apparatus and more particularly to air actuated control apparatus including a snap actuated switch of the toggle operated type to quickly make and break 5 a circuit therethrough.

Heretofore in control apparatus using snap actuated switches for making and breaking electrical circuits, there has been considerable difficulty in providing snap actuating switches that will apply heavy pressure to the switch contacts up to the instant of contact separation. It has been found that in snap" switches, when actuated slowly, the'c'ontact pressure between the contacts gradually diminishes until they are separated. It has also been found that when snap switches are actuated slowly and the switch approaches the breaking point the'contact pressure becomes substantially zero-thus causing excessive arcing and burning of" the contacts.

An object of the present invention'is to provide a switch which will operate with aquick and snap action, and at the same time provide means to apply'hcavy pressure to the switch contacts upto the instant of the break of the contacts and thereby substantially eliminate arcing and burning: of the contacts.

Another'object of th'epresent invention is to provide a switch structureiafiected by an air stream thatwill automatically effect a quick make and break :of circuit connections in response. to slight changes of air currents after the air currentslreach acertain velocity.

--Another objcctof the present invention is to provida'an-air controlled snap switch adapted for usein remote volume control of a radio in automotive vehicles-wherebythevolume can be automatically. increased at a. predetermined speed of the vehicle. and againudecreased when the speed of the vehicle falls below that predetermined speed. w

Further objects and. advantages of the present inventionxwill' 'beapparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

Inthedrawing:

Fig. l/is a plan view, on anenlarged scale, with the cover shown. in section, and showing the switch elements in their normal positions.

Fig. 2 is a sectionalview taken substantially on line 2--2 of Fig, 1. a

Figs. 3, 4and:5.w.aresectional views taken on lines .3-3, 4+4 and 5.'5 respectively of Fig. 2.

U Referring to the. drawing, a base insulatingly supportsa pair of terminals 2| and 22. The

base 20 is provided with a central opening 23. The portion of the base margining the aperture is inwardly extended to provide a tongue 24. A bearing sleeve having a longitudinal groove 26 on the outer surface is secured to the base. The sleeve is provided with an enlarged intermediate portion including a collar portion 2'! and a hub portion 28, the collar portion engaging one side of the plate and hub portion projecting through the opening. The tongue 25 of the base fits into the groove 26 and prevents the sleeve from rotating relative to the base. The sleeve is held firmly to the base by deforming the hub portion 28 against the base as indicated at 29, see Fig. 2.

A shaft 32 is jcurnaled in the sleeve 25 and projects beyond one end thereof, and is provided with a reduced end ill. The shaft is prevented from moving axially in one direction in the sleeve 25 by a pin 32, the pin is press-fitted in a transverse opening in the shaft. A thrust washer 33 is interposed between the pin and the end of the sleeve 25.

A metallic sleeve 35 is mounted upon the sleeve 25 and includes a restricted portion 38 to provide a shoulder 31. The restricted portion is continued inwardly to form an opening 38. The portion of the metal about the opening 33 is inwardly extended to form a tongue 39 which fits into the groove 26 of the sleeve 25 to prevent the sleeve 35 from turning relative to the bearing sleeve 25. A hub 49 is secured to the shaft by a pin 4|. A fan blade or vane 42 is secured to the hub by spinning over a reduced portion of the hub, which projects through an opening in the blade and spun over the blade as clearly shown at 43, see Fig, 2. A coil spring 44 is interposed between the shoulder 31, provided on the sleeve 35, and the blade 42. The spring biases the blade 42 in a counter-clockwise direction as viewed in Fig. 1. This is accomplished by anchoring one end 45 of the spring in one of the openings 31a provided in the shoulder 31 and the other end 46 of the spring is anchored in an opening provided in the blade 42. The tension of the spring may be increased or decreased by shifting the end 45 from one opening to another. A weight 48 is attached to the end of the vane 42 so as to stabilize the action of the vane 42 in its movements from one position to another.

A movable contact 50, having contact lugs or cars 5| and 52 and a pivot member 53, is pivotally supported in the groove 26 of the sleeve between the tongue 24 and the washer 33. The washer 33 and the tongue 24 cooperate to limit endwise movements of the contact 50 within the groove 54. This pin has an annular groove 54a which serves as a pivot for a toggle mechanism 55 which operates to hold the contact 50 firmly against the terminals 2| and 22, depending upon the position of the toggle mechanism 55.

The toggle mechanism 55 comprises a lever 53 of insulating material having a slot 51 to receive the pin 54 which forms a pivot for the lever This lever is also provided with a cutout portion 58 through which the sleeve and the pivot member 53 of the contact 50 extend. A coil spring 5.; is arranged between the lever 55 and a stationary post (it carried by the base 20. The spring is provided with hooks El on its ends adapted to be received in notches 62 and 63 of the lever 56 and post 60, respectively. The spring 5:! operates to hold the pin 54 in the groove 25 and maintains the lever 55 past dead center so that the contact 50 will be held firmly against one or the other of the terminals 2| and 22.

A second toggle E5 is pivctally supported upon the reduced end 31 of the shaft 38 and comprises a movable lever 53. This lever is provided with an opening 6! and an annular recess 68 around the opening to provide a shouder E9. The opening receives a hub portion of bushing The hub portion is deformed against the shoulder as at ll, to hold the bushing firmly to the lever. The enlarged portion of the bushing is counterbored in such a manner, as at it, so as to reduce friction between the bushing and the shoulder of the shaft forme" by the reduced end 3i. The enlarged portion of the bushing is provided with diametrically disposed notches IS. The notches 73 receive the protruding ends of the pin 32. These notches are of such width as to permit considerable lost motion between the pin ends and the hub as shown in Fig. l. By this means the initial turning of the shaft will not actuate the lever The lever 66 carries a pin 7:": having ends '15 and W extending on opposite sides thereof, the end ll extending toward the movable contact and located between the ears 5i and 52. The end of the pin '5 is provided with an annular groove which forms a pivot for an insulating lever 73. The lever T8 is provided with an opening or slot 19 adapted to receive the pin and rest in the annular groove of the pin. The lever 18 is provided with a cutout portion or opening 80 through which the reduced ends of the bushing 10 and shaft end 3! project. This arrangement of the parts is desired as it economizes on space. A coil spring 8! is arranged between the lever 18 and the stationary pin. The spring 8! is provided with hooks 82 on its ends adapted to be received in notches S3 and 84 of the lever l8 and post 6!] respectively. This spring operates to hold th lever in the annular groove of pin end iii and hold the lever past its ead center.

A cover is provided to enclose the toggle mechanisms and E5 and is held to the base by a screw S! having screw thread engagement with the base.

in operation with the parts of the various mechanisms in their normal position as shown in Fig. 1 of the drawing, the spring 5; normally urges the vane 12 in a counter-clockwise direction. When the vane 52 is sub-jec'ed to c rrents of air the vane will rotate the shaft in a clock s direction against the tension of coil spring 44. As the shaft 351' is rotated th ends of the pin 32 first travel a considerable distance before they engage the shoulders 95 of notches 13, see Fig. 4. When the ends of pin 32 thus engage the shoulders 95 the lever will then be driven by the pin. The movement of the lever 66 swings the lever I8 on its pivot 16 and when the lever reaches a position where the upper end of the spring BI is past the axis of the shaft the tension of the spring 8| will move the lever 18 with a snap action and carry the lever 66 through the lost motion connection in the same direction. The lost motion connection between the shaft 30 and lever 66 is sufficient to cause the pin end TI to engage the ear 5| and knock contact over its dead center in the same direction. When the lever 56 is shifted past its dead center by the contact 50 the tension of the spring 59 will then operate to hold the ear 5| of the contact 50 firmly against the terminal 2|. The operation of the toggle mechanisms 65 and respectively just described is the same in the reverse directions when the currents of air against the vane 42 are not strong enough to overcome the tension of the spring 44.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An electric switch comprising, a shaft operated by an actuator, a bearing sleeve for the shaft, a lever loosely journalled on the shaft, a lost motion connection between the shaft and the lever, a spring connecting the lever with a fixed point and having its center line of action moved from one side to the other side of the axis of the shaft by movement of the lever, thereby changing the bias of the spring to move the lever clockwise or counterclockwise, a switch arm having one end pivoted on the bearing sleeve and the other end movable between two stops, means for yieldingly maintaining the arm in engagement with either of the stops, and a lost motion connection between the lever and the switch arm.

2. An electric switch comprising, a. shaft operated by an actuator, a lever loosely journalled on the shaft, a lost motion connection between the shaft and lever, a spring connecting the lever with a fixed point and having its center line of action moved from one side to the other side of the axis of the shaft by movement of the lever, thereby changing the bias of the spring to move the lever clockwise or counterclockwise, a pair of spaced stationary stops, a. switch arm having a pair of spaced lugs, for engaging the stops, means yieldingly maintaining one or the other of the lugs in engagement with one or the other 01 the stops; and a pin carried by the lever and movable between the lugs of the switch arm.

3. An electric switch comprising, a shaft operated by an actuator, a lever loosely journalled on the shaft, a lost motion connection between the shaft and lever, 21 pair of stationary stops a witch arm movable between the stops and pivoted on a bearing sleeve which supports the shaft, a spring for maintaining the arm in engagement with either of the stops, a lever actuating spring connected at one end with a fixed point and at the other end with the lever, said lever carrying a pin, and a device cooperating with the pin for attaching the end of the spring to the lever, yet permitting lost motion actuation of the lever.

4. An electric switch comprising, a shaft operated by an actuator, a lever loosely journalled on the shaft, 21 lost-motion connection between the shaft and lever, a pair of stationary stops; a switch arm movable between the stops and pivoted on a bearing sleeve which supports the shaft, a spring for maintaining the switch arm in engagement with either of the stops, a switch actuating spring connected at one end with a fixed point and at the other end with the lever, said lever carrying a pin, and a device cooperating with the pin for attaching the end of the spring to the lever, said device comprising a part which encircles the shaft and is attached to the pin which is on the side of the shaft remote from the point of connection between the switch actuating spring and the fixed point.

5. An electric switch having an arm movable between two spaced stops, an operating shaft, a lever loosely journalled on the shaft for actuating the arm, a lost motion connection between the shaft and lever, a second lost motion connection between the lever and arm; a spring for maintaining the arm in engagement with either of the stops, said spring having one end connected to a fixed point and the other end connected with a part of the arm remote from the fixed point and on the other side of the arm pivot through the use of a member which encircles the shaft whereby the center line of action of said spring is moved from one side of the pivot of the arm to the other side as the arm is moved from one stop toward the other, a lever actuatin spring, said spring having one end connected to a fixed point and the other end with a part which encircles the shaft, said part being attached to the lever on the side of the shaft remote from the point of connection between the spring and the fixed point whereby the center line of action of the lever actuating spring with respect to the axis of the shaft is shifted from one side of the axis of the shaft to the other side by movement of the lever as effected by the shaft through the lost motion provide the fixed points for the springs.

ROBERT H. HILL. 

